Cooperative amplify-and-forward scheme based on multi-access channel

We present a novel cooperative amplify-and-forward (AF) scheme for multi-access channel with two sources. The scheme achieves the maximum diversity order while keeping the loss of spectral efficiency as minimal as possible by allowing each source to transmit and relay simultaneously. It turns out that the diversity multiplexing tradeoff (DMT) achieved by the proposed protocol is very close to the MISO upper bound when the frame length is large enough.